The present invention resides in the field of glass molds, and more particularly relates to an improved mold mechanism for opening and closing split molds utilized in blown glassware.
In the formation of hollow glassware, a charge of molten glass is usually initially formed into a parison such as by pressing or blowing such charge within a parison mold, and the thus formed parison is then transported to a blow mold for blowing the same into a finished article. Thus, it is necessary for the blow mold to open sufficiently to receive the preformed parison, close so as to form the desired mold cavity for blowing the parison into a finished article, and again open sufficiently wide so as to permit the removal of the finished article from the mold. Although some press and blow operations are accomplished with the blow mold in a stationary position, other operations include the utilization of a plurality of such blow molds positioned about a rotating table which successively receive a preformed parison carried by a conveyor, such as shown in U.S. Pat. Nos. 2,263,126 and 3,622,305.
The mold mechanism of U.S. Pat. No. 2,263,126 accomplishes both a straight line motion of the back half of a blow mold and a rotary motion of the front half of the blow mold from a single straight line driving motion imparted by an air cylinder. However, the mechanism of such patent utilizes a rack and pinion to provide the rotary motion to the front blow mold half, and due to constant wear and backlash between the rack and pinion, the mechanism becomes loose and erratic and accordingly affects glass quality produced thereby. Further, pieces of glass have a tendency to become lodged within the rack and pinion mechanism thus producing the jamming thereof and undesirable downtime.
It thus has been an object of the present invention to overcome such problems which existed with the prior art devices and provide a smooth operating mold mechanism for opening and closing the mold halves of a blow mold.